Gender locked race?

[Iscah]

There was a sahagin priest that used the echo and ended up being devoured by leviathan. Go back and re-watch the leviathan arc cutscenes in the armoire.

It seems like he was directly gifted the Echo by Elidibus. I also think it's possible he was actually made into an Ascian (with the purple aura and that weird 'growling' noise that seems to accompany Ascians using their abilities).

(Also, nitpicky but you want the Unending Journey for cutscene reviewing. The Armoire is for storing gear.)

Ants? An Ant race? I'm not sure if Worker Ants can be female or not, but there's a clear difference between a Worker and a Queen ant. Similar to this Viera and Mi'qote setup, the queen is kept in safety for breeding, pretty much.

Worker ants (and bees) are all female. The males only exist to breed with the queen. (That's the simple generic version anyway - but definitely workers are female.)

idk but there was word of another version of viera that would be shorter, and those weren't shown either. I don't think we've had two different sub-groups of a race since hyur - midlander and highlanders. If there really are going to be two sub-groups of viera, along with male viera, then I could understand why they are saving that reveal for a different fanfest.

As far as I'm aware, that theorising is built off concept art and Viera in other games. However, the Wandering Dramaturge's lore-dump for Viera only mentioned light-skinned and dark-skinned clans - and not even separate cultures for the two. I actually find that more worrying than the lack of visible males right now.

They really aren't abundant though. Racking my brain I can think of....

I was making a list of Sunseeker characters (both for name reference and for trying to identify all the members of the different tribes) a while back, so I have a reference for those! Still might have missed one or two, as I just had to trawl through Garland Tools' lists of NPCs by area - and also will have missed anyone identified by a label rather than a name. Can't find the Ul'dahn merchant in Kugane that you mentioned.

A'aba Tia - one of Arenvald's friends in early ARR; killed in the raid on the Waking Sands.
B'benha Tia - squadron lancer
C'zibho Tia - Moonfire Faire 20__
D'fhul Tia - squadron conjurer
G'raha Tia - Crystal Tower raids
H'raha Tia - MNK 50-60
J'zula Tia - Resistance member at Porta Praetoria
K'rhid Tia - ACN guildmaster
M'rahz Nunh and M'zhet Tia - M tribe at the Peering Stones
O'bhen Tia - a hunter at Tailfeather
R'fhul Tia - Moonfire Faire 2018
R'mhasi Tia - CUL 50-60
U'odh Nunh, U'khuba Tia and U'tykha Tia - U tribe at Forgotten Springs
V'mah Tia - Scion since post-ARR
X'rhun Tia - RDM tutor

(that's 18 characters vs about 120 on the list of females)

For Moonkeepers, I don't have a list, but as well as those you mentioned (the Beast Tribe villain and the Couerlclaw King) I can think of one from the BLM 50-70 quests.